Re: [APML] September Images Posted

[Chris1011@aol.com]

In a message dated 10/12/2001 8:21:48 AM Pacific Daylight Time, jkolb@mindport.com writes:


> I'm noticing blue fringing on stars with
> this configuration, so either it's not well-corrected for blue at f/4 (most
> likely), focus is slightly out, or maybe the collimation needs to be
> checked.  


I'm hard pressed to see much blue fringing. Please note - collimation changes the shape of the stars from round to oval or in extreme cases seagull shaped. Miscollimation does NOT introduce the following: spherical aberration, zones, turned edge, chromatic aberration, loss of contrast, wavering images, etc etc. There is a growing trend in all the newsgroups for people to suspect their collimation when the problem is actually caused by optical defects, atmospheric unsteadiness, or lack of cooldown.

Roland Christen